Through conductor relay with detachable armature assembly



June 26, 1951 J. wURGLr-:R 2,558,640

THROUGH CONDUCTOR RELAY WITH OETAOHABLE ARMATURE ASSEMBLY 3 Sheets-Sheetl Filed June 8, 1948 June 26, 1951 J. wURGLl-:R 2,558,640

THROUGH CONDUCTOR RELAY WITH DETACHABLE ARMATURE ASSEMBLY 3 Sheets-Sheet2 Filed June 8, 1948 June 26, 1951 RGLER 2,558,640

J. WU THROUGH CONDUCTOR RELAY WITH DETACHABLE ARMATURE ASSEMBLY FiledJune 8, 1948 3 Sheets-Sheet 3 Patented June 26, 1951 THROUGH CONDUCTORRELAY WITH DETACHABLE ARMATURE ASSEMBLY John Wurgler, Milwaukee, Wis.,assigner to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., acorporation of Delaware Application June 8, 1948, Serial No. 31,698

(Cl. 20G-87) 2 Claims.

This invention relates in general to improvements in relays, and moreparticularly to through conductor current relays.

Through conductor type relays are mounted so that a bus bar or cablepasses through its magnetic core. For mounting the relay it is generallynecessary to remove the frame and the armature from the core. In doingso the adjustments of the relay which determine its operatingcharacteristics are disturbed, requiring the relay to be readjusted oradjusted only after it is installed.

It is therefore advantageous to use a through conductor type relay whichcan be disassembled for mounting the relay without disturbing any of itsOperating adjustments. A preferred embodiment of such a relay comprisesa balanced armature supported on a frame which is removably mounted on aU-shaped core. Another preferred embodiment is a relay comprising anarmature pivoted on a leg of the core and supported on the frame whenthe frame is removed from the core.

It is therefore an object of the invention to provide a throughconductor type relay that can be readily mounted on a cable or bus bar.

Another object is to provide a through conductor type relay which may bedisassembled in two parts for mounting on the cable or bus bar.

Another object is to provide a through conductor type relay which may bedisassembled for mounting on the conductor Without disturbing theadjustment of the armature.

Another object is to provide a through conductor type relay with a coilwhich may be slidably mounted on a leg of the core and readily removedwhen the frame is removed from the core.

Another object is to provide a through conductor type relay which may bemounted in any position.

Another object is to provide a through conductor type relay which issubstantially shockproof in operation.

Other objects and advantages will be apparent from a consideration ofthe following description taken in connection with the accompanyingdrawing in which:

Fig. 1 is a view in side elevation of a balanced armature throughconductor type relay showing a coil mounted thereon and a normally opencontact assembly;

Fig. 2 is a plan view of the relay shown in Fig. 1:

Fig. 3 is a right end view f the relay shown in Fig. 1;

Fig. 4 is a partial left end view of the relay shown in Fig. 1;

Fig. 5 is a view in side elevation of another through conductor typerelay having a clapper type armature and a normally closed contactassembly;

Fig. 6 is a plan view of the relay shown in Fig. 5;

Fig. 7 is a right end view of the relay shown in Fig. 5;

Fig. 8 is a partial left end view of the relay shown in Fig. 5 with thecover broken away;

Fig. 9 is a cross sectional View taken along the line IX-IX of Fig. 6;

Fig. 10 is a View of the relay shown in Fig. 1 modiiied by addition of acoil thereon and by rearrangement of the contact assembly to providenormally closed contacts; and

Fig. 11 is a view of the relay shown in Fig. 5 modified by rearrangementof the contact assembly to provide normally open contacts.

Referring more particularly to the drawings by characters of reference,the preferred embodiment of relay illustrated in Figs. l to 4,inclusive, comprises a U-shaped magnetic core I2 having two legs I3, I4.Leg I4 is shorter than the other and has a iiat end forming a pole platefor one end of the relay armature. The longer leg I3 is provided with arectangular slot giving a U- shaped appearance to the end of the leg.The bottom of the core is provided with a pair of drilled and tappedholes I6 for fastening the core in any suitable known manner. The coremay be made with any required depth for mounting on bus bars ofdifferent predetermined sizes.

A frame of nonmagnetic material, such as brass, is mounted on the core.The frame comprises a plate I8 and a pair of spacers I9 integral Withthe plate for supporting the frame on the shorter leg I4 of the core. Apole plate or bridge 20 of magnetic material is seated on the leg I3 andbridges its slot to define an opening I5. This bridge 28 is fastened tothe plate I8 by screws 2|. Screws 23 and screws 22 which pass throughthe bridge, fasten the frame to the legs of the core. Leg I4, plate I8,and spacers I9 define an opening 24 similar to opening I5.

Pivot supports 26 yare united to the plate I8 to form a part of theframe. The supports are located substantially midway of the two corelegs, and each has a drilled and tapped hole 2l for receiving a threadedpivot member 28.

Each pivot member 28, besides the threaded portion, has a smallercylindrical portion 3D, forming a pivot with a rounded or ball point lend. The pivot member is locked to the support comprises two pairs offixed contacts 34 sup-Y ported on the frame, and two pairs of movablecontacts 35 supported on the armature. A block 36 of any suitable knowninsulatingV material is fastened to the frame by screws: 2l, 22; The

block 36 is provided with four threaded studs 3'I for connecting leadsthereto andfor'supporting Each .stud 31 is. locked in position by locknuts 39; The lower" two pairs of fixed contacts 34.

end of each stud defines a xed contact 34, and is silver tipped to formagood Contact surface. Each studA 3'I may; alsoy be tapped for receivinga head screw, the head of which defines a fixed contact.

Fastened to armature 4I as by rivets 42, a sup-- port arml 43. ofsuitable. insulating material, eX- tends under the block 36. The supportarm-43 carries a pair of resilientbridge contacts-35.each fastened by ascrew 44 and nut A5 so that each pair ofbridge contacts35alignswithapairof the xed contacts 34. Each of the resilient bridge contacts comprisesa pair of contacts-conductively connected together by aresilient bridgemember fastened tothe arm 43. A shield 46 may be provided for the bridgecontacts and may: besupportedl by the support arm 43 and fastenedthereto byv screws II-provided0 with collarsfl between theybridgecontactand the shield.

A transparent protecting cover #.8 is provided for the, contact assemblyand is fastened to the block 36 by screws 49.

A nonmagnetic bar I is. attached to one end of the armature to balancethe armature with thek movable contacts supported at the other endthereof.- The armature being balanced in all positions, therelay. isVshockproof in operation.

Al spring. 52 is seated in a recess 53 of plate I8, and the springis-mounted on a threaded Stucl'SE-whichv is united with the'armature 4I.

The spring is.k held under compression between nuts 54 and the plate I8for biasing armature -twoair gaps, one between armature 4I and thefendofk leg Il,and the other between the armature and bridge seated onleg I3. When the-armature is in the biased position Vshown away from thecore, ther air gaps are relatively large and are called pickup air gaps;when the armature is attracted, the air gaps are relatively small andarecalled-the drop outairgaps.

The flux in thel air gapsat each end of the armature cooperate to ,giveva torque tending to pivot the armaturer in the same direction.

Also mounted in the frame are air gap adjusting screws 51, 58. Screw 58Ais located in plate I8 for contacting the armature near'the short leg toprovide a pick up'air gap adjustment. Screw 5'I is `located in plateI8extending through block 36, plate I8, and pole plate-Z'for contacting;the armature near the longer leg to provide a dropout air gapadjustment.

The relay may be provided with a coil 66.

' tached to the armature.

mounted on a leg of the core for either independent operation of therelay or diierential operation with the through conductor. The coil isconstructed with an opening for fitting the leg of the core. A clamp 6Iextending through the opening in the coil has bent up portions 62 forretaining the coil therebetween. Another portion 63 of the clamp 6Iprovides a hole for receiving a screw 64 to bind the clamp to the leg ofthe core. The clamp is also held to the core by the coil which itretains from longitudinal movement-on the core leg.

To' assemble the relay, pole plate 20 and the fixed Contact assemblycomprising block 36 are mounted on the' frame and fastened thereto byscrews 21,22; The bridge contacts are mounted on the arm support whichis permanently at- The armature mounted stud 55 is inserted into thehole 56 of the plate I8 and the armature is supported on the frame bythepivots 30. whichare insertedinto the openings` in. the. opposite sidesof the armature.. The pivots are pressed finger-tight againstthearmature by turning the pivot members 28 in the supports 26. When theside play ofthe armature is taken up, the pivot` members are locked` bytightening` lock. nutsV 3l. BiasI spring 52 is inserted in recess. 53over the threaded stud 55. The spring is compressed byv screwing locknuts 54 on the stud. The set. screws 5l, 58, alsoprovided with locknuts, are screwed into-the. plate. The cover l is mounted onblock. 36toY protect the. contact assembly.

The coil. 6 may be. mounted on a leg of the core with the clamppreviously insertedr in the coil.V The coil andclamp 6I. are slidablymoved into position` on the. leg and the screw 64 insertedto hold thecoilin place.

The frame then is mounted on the,4 core. with the bridger 2U seated onleg I3. and the. spacers I9 seated on leg Ill.

To properly adjust the relay, it may be test mounted and its coreexcited by predetermined values of magnetomotive` force. by a` conductorpassing through the coreA or by a coil mounted on a core leg. Althoughthe relay may be mounted in any position, for precise adjustment it isbest to test mount it in the saine position it will assume in aninstallation in which it is to be'usedV When the armature is in theunattracted position, the pick up air gap is adjusted by screw 58 sothat the armature is attracted by a predetermined value of'magnetomotiveforce fora given bias force on the armature due to spring 52. For agiven pick up air gap and magnetomotive force, the bias of spring 52 isdecreased until the armature is attracted to the core.

When the armature is in the attracted position, the drop out air gapsare adjusted by screw 57 until'the armature returns to the biasedposition shown for another predeterminedl value of magnetomotive force.

relay is not energized and make good contact when the relay isenergized.

The relay, when thus properly adjusted, is ready to be mounted on acable or bus bar; The

screws-22., 23 are removed, freeing the U-shapedv core I2 from theframe. The armature 4I remains supported on the frame and none' of the1adjustments is disturbed. The U-shaped core I2;

s. is ythen suitably mounted on the cable or bus bar with the cable orbus bar intermediate the legs of the core. the core and the screws 22,23 replaced.

The relay may also be provided with a contact assembly comprisingnormally closed contacts as shown in Fig. l0. The plate I3 is providedwith holes for receiving screws '2| for then mountn ing the block 3S onthe other end of the frame. Blcok 36 is provided with a hole 4D forreceiving stud 55 and spring 52. Studs 31 in block 36 are screwed so xedcontacts 34 are brought near to block 36. Arm 43 supporting the bridgecontacts 35 is mounted on the upper side of armature 4| at the endadjacent leg I4. The bar 5| is mounted on the underside of the armatureat the end adjacent leg I3. The relay is adjusted as before except thatthe contacts are closed when adjusting the pick up gap, and the contactsare open when adjusting the drop out air gap of the relay.

The relay illustrated inl Figs. 5 to 9, inclusive. comprises an armature61 pivoted on a leg 68 of, a U-shaped core 69. The leg 68 is beveled toform a knife edge fulcrum 18. and the armature has a notch 9|]cooperating with the fulcrum for pivotally supporting the armature onthe core leg.

The nonmagnetic frame comprises a plate 1|, spacers 12, and an armatureguard 13. The armature guard 13 is fastened to the plate 1| by screws14, and the guard is spaced from the plate by collars 15 through whichthe screws 14 extend.

The frame is mounted on the legs of the core and fastened thereto byscrews 81 and 92. The armature is biased against the fulcrum by a spring16 seated in both the armature and the plate 1| and positioned betweenthem above the fulcrum.

Stud 18 is mounted on the armature 61 and extends freely through plate1| and insulating block 82. `Over stud 18, spring 19 is mounted andseated in plate 1|. A stud 8| extending through block 82 is mounted inplate 1| and extends freely through the armature 61. Over stud 8| biasspring 83 is mounted and positioned in a recess in armature 61. Spring19 biases the armature away from leg 80 toward its unattracted positionagainst a stop r85 integral with plate 1| Stop `85 determines the pickup air gap of the relay. Spring l83 is mounted on the stud 8| with freeplay thereon when the armature is in the unattracted position. Spring 83cooperates with spring 19 to bias the armature away from leg 80 when thearmature approaches the lattracted position.

When the frame is removed from the core, the armature 61 is supportedthereon. Bias spring 16 then forces one end of the armature against arivet 11 in the guard 13, and spring 19 pulls the other end of thearmature against stop 85.

Relay 66 is shown having a pair of normally closed contacts and `a pairof threaded studs 84 for connecting lead wires. Fixed contacts 86 andstuds 84 are supported in block v82 which is mounted on the frame. Guardretaining screws 14 also fasten the block 82 to plate 1|. Theblock 82 isalso bound to plate 1| by a pair of screws 81 which with screws 92attach the frame to the core.

Bridge contacts 88 comprising the movable contacts of the Contactassembly are supported on an arm 89 extending from and attached to thearmature. The contact assembly is also provided with a transparent cover9|.

As in the case of the embodiment illustrated in Figs. l to 4, inclusive,the relay may be mounted The frame is again mounted on in any positionand maybe test mounted and operated for adjusting the drop out and pickup characteristics of the relay. In the unattracted position of thearmature it remains biased away from core leg V by spring 19 whichdetermines the pick up of the armature. Spring 19 is adjusted so that apredetermined value of magnetomotive force will cause the armature tomove toward core leg 88, taking up the free play of spring 83 on itsstud. Further attraction of the yarmature compresses spring 83 as Wellas continued compression of spring 19. Spring 83 requires greater forceto compress it than spring 19. '.'CheV springs 19 and 83 are chosen withforce characteristics which cooperate to bias the armature closely tothe characteristic of the magnetic at? tractive force acting on thearmature as the air gap decreases when the armature moves toward coreleg 88.

When the pick up value of the relay is adjusted,

the stud 8| supporting spring 83 is turned to in.

crease or decrease the free play of the spring slidably mounted onthestud between the head thereof and the armature. Decreasing the free playincreases the bias and brings the drop out characteristic closer to thepick up characteristic. This larrangement permits the drop out to beadjusted Very closely to the pick up Value.

Removing the four head screws 81 and 92 permits removal of the core fromthe frame on which the armature remains supported. The core may bemounted in a known suitable manner on a cable or bus bar, and the frameremounted on the core and the head screws replaced without disturbingthe adjustment of the armature.

The relay may also be provided with a contact assembly comprisingnormally open contacts as shown in Fig. 11. For normally open contacts,two U-shaped brackets 93 are mounted on studs 84. Each bracket 93supports a xed contact stud 94 aligned below a contact of invertedbridge contacts 88. The brackets 93 conductively connect the fixedcontact studs 94 to the studs 84 to which leads are to be connected. Therelay is adjusted as before, taking into account that the contacts areopen when adjusting the pick up value of the relay, and the contacts areclosed when adjusting the drop out value of the relay.

Although the relays herein described are referred to as of the throughconductor type, they may be operated by at least one coil mounted on acore leg, or differentially operated by a pair of coils or a coil and athrough conductor.

It is claimed and desired to secure by Letters Patent:

1. An electromagnetic relay comprising a U- shaped magnetic core havingrst and second legs dening a passage for the insertion of a currentcarrying conductor, said first core leg being provided with a slot, anonmagnetic frame removably mounted across said core legs to permitinsertion of said conductor in said passage, a bridge of magneticmaterial mounted on said frame across said slot between said frame andsaid first core leg to denne an opening, a pair of pivot members mountedon opposite sides of said frame, an armature having a pair of recessesprovided on opposite sides thereof at points substantially equidistantfrom the ends thereof, said pivot members engaging said recesses wherebysaid armature is pivotally positioned with one end extending into saidslot of said rst core leg and the other end disposed adjacent to saidsecond core leg, a stud attached to said other end of said armature andextending freely through said frameastinprz means. attacheftit'orthesendf of'i saidV studi. a; spring? tted;AA overt? said studi7 and.come pressed'betweensaid stopmeansandsaid iframey toc-bias' saidarmature, adjustable=screw:l means mounted on said"f.rame forvad;j1"1stingthe :air gaps between vsaid armature ends and saidy corelegs, aa'rst member' of i' insulating material. attachedtofsaid'fonewendof said amature and :extending through said; slot',Y aresilient bridge member Irounted^onsaidinsulating member, arstpair'ofcontactsrmounted on said' resilient bridge memberand"'condctive'1y:connected thereby, asecond insuiating;member.;attached'to` said frame adjacent ter-said s1ot,"af second pairofcontacts distinct v.from saids'crew 'i meansfmounted Aionrsaidecondinsu-f lating memberand enga'geablez-with said -rstzpair oflontacts inresponse tto movement of said armae tureagainst 'theaetionof ysaid'springpand means for adjusting the distance between saidrst and saidfsecond `pairv of"contacts When-userid' pairsfof contactsfaredisengaged:

2? Ani' electromagnetic relay operable: in respenseto therfl'ow of"current through aiV conductor;- said relayrcompris'ing a`` U lshapedmagnetic eorefliavingistiand second 'legs defining a pas sagefor theinsertionfof said conductor,` said first coreffleg. Abeing llonger thansaid 'second core'1eg and having'a slot at its end,` a-nonmagnetic frameremovably mounted across said 'core 1egs"toper mit "insertion" of 'saidconductor vin said: passage, pivot means mountedr'on' said: framaanelongated armaturesupported at a2 point. intermediate ytheends'lth'ereof` on! saidipivot. means. to .form With said corea1magnetic circuit in which' magneticux is producedbysad ow'l'ofcurrenteoneofthe endseof samiarmature: extending@ into: saidz slotandtire others'enti?.A of sax-idf; armature-e extending;- betweezrsaid:frame and-'isaid'second 'corelegfsaid second core; legir forming gafapole plate-f fonY said otherend of. sa-idf A, armature and defining.,therewithY air *gap-einsam', magnetic .,circut, d and. abridgeoffmagneticv materia1--secured-to saidirst core leg acrossfsaidslot l forminga,po1e p1ate ,for saidnonegend ,ofi-said armature A,andLdeninggtheref with a. second air.A gap.insaidl. magnetic circuit,wherebysaidg ux; causes said. one. end of said armature Itofbeattractedatowardr'said bridgealld saidother,Y end of .lsaidlraxmatur'eeto be kryattracted'l toward 4said:secondcoredeg.`A to..cause,rotation ,Voir

said armaturezabout saidpivot means.v

JQHN .WURGLER- REFERENCES" CITED The@ollltlwing;` ref extensas?, are; ofrecord 1 inf. the le of this patent:

UNITED STATES PATENTS Ray; Aug 7,"1 1945"

